# Net::Netrc.pm
#
# Copyright (c) 1995-1997 Graham Barr <gbarr@pobox.com>. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.

package Net::Netrc;

use Carp;
use strict;
use FileHandle;
use vars qw($VERSION);

$VERSION = do { my @r=(q$Revision: 2.6 $=~/\d+/g); sprintf "%d."."%02d"x$#r,@r};

my %netrc = ();

sub _readrc
{
 my $host = shift;

 # Some OS's don't have `getpwuid', so we default to $ENV{HOME}
 my $home = eval { (getpwuid($>))[7] } || $ENV{HOME};
 my $file = $home . "/.netrc";

 my($login,$pass,$acct) = (undef,undef,undef);
 my $fh;
 local $_;

 $netrc{default} = undef;

 # OS/2 does not handle stat in a way compatable with this check :-(
 unless($^O eq 'os2')
  { 
   my @stat = stat($file);

   if(@stat)
    {
     if($stat[2] & 077)
      {
       carp "Bad permissions: $file";
       return;
      }
     if($stat[4] != $<)
      {
       carp "Not owner: $file";
       return;
      }
    }
  }

 if($fh = FileHandle->new($file,"r"))
  {
   my($mach,$macdef,$tok,@tok) = (0,0);

   while(<$fh>)
    {
     undef $macdef if /\A\n\Z/;

     if($macdef)
      {
       push(@$macdef,$_);
       next;
      }

     push(@tok, split(/[\s\n]+/, $_));

TOKEN:
     while(@tok)
      {
       if($tok[0] eq "default")
        {
         shift(@tok);
         $mach = bless {};
   	 $netrc{default} = [$mach];

         next TOKEN;
        }

       last TOKEN
            unless @tok > 1;

       $tok = shift(@tok);

       if($tok eq "machine")
        {
         my $host = shift @tok;
         $mach = bless {machine => $mach};

         $netrc{$host} = []
            unless exists($netrc{$host});
         push(@{$netrc{$host}}, $mach);
        }
       elsif($tok =~ /^(login|password|account)$/)
        {
         next TOKEN unless $mach;
         my $value = shift @tok;
         $mach->{$1} = $value;
        }
       elsif($tok eq "macdef")
        {
         next TOKEN unless $mach;
         my $value = shift @tok;
         $mach->{macdef} = {}
            unless exists $mach->{macdef};
         $macdef = $mach->{machdef}{$value} = [];
        }
      }
    }
   $fh->close();
  }
}

sub lookup
{
 my($pkg,$mach,$login) = @_;

 _readrc()
    unless exists $netrc{default};

 $mach ||= 'default';
 undef $login
    if $mach eq 'default';

 if(exists $netrc{$mach})
  {
   if(defined $login)
    {
     my $m;
     foreach $m (@{$netrc{$mach}})
      {
       return $m
            if(exists $m->{login} && $m->{login} eq $login);
      }
     return undef;
    }
   return $netrc{$mach}->[0]
  }

 return $netrc{default}->[0]
    if defined $netrc{default};

 return undef;
}

sub login
{
 my $me = shift;

 exists $me->{login}
    ? $me->{login}
    : undef;
}

sub account
{
 my $me = shift;

 exists $me->{account}
    ? $me->{account}
    : undef;
}

sub password
{
 my $me = shift;

 exists $me->{password}
    ? $me->{password}
    : undef;
}

sub lpa
{
 my $me = shift;
 ($me->login, $me->password, $me->account);
}

1;

__END__

=head1 NAME

Net::Netrc - OO interface to users netrc file

=head1 SYNOPSIS

    use Net::Netrc;
    
    $mach = Net::Netrc->lookup('some.machine');
    $login = $mach->login;
    ($login, $password, $account) = $mach->lpa;

=head1 DESCRIPTION

C<Net::Netrc> is a class implementing a simple interface to the .netrc file
used as by the ftp program.

C<Net::Netrc> also implements security checks just like the ftp program,
these checks are, first that the .netrc file must be owned by the user and 
second the ownership permissions should be such that only the owner has
read and write access. If these conditions are not met then a warning is
output and the .netrc file is not read.

=head1 THE .netrc FILE

The .netrc file contains login and initialization information used by the
auto-login process.  It resides in the user's home directory.  The following
tokens are recognized; they may be separated by spaces, tabs, or new-lines:

=over 4

=item machine name

Identify a remote machine name. The auto-login process searches
the .netrc file for a machine token that matches the remote machine
specified.  Once a match is made, the subsequent .netrc tokens
are processed, stopping when the end of file is reached or an-
other machine or a default token is encountered.

=item default

This is the same as machine name except that default matches
any name.  There can be only one default token, and it must be
after all machine tokens.  This is normally used as:

    default login anonymous password user@site

thereby giving the user automatic anonymous login to machines
not specified in .netrc.

=item login name

Identify a user on the remote machine.  If this token is present,
the auto-login process will initiate a login using the
specified name.

=item password string

Supply a password.  If this token is present, the auto-login
process will supply the specified string if the remote server
requires a password as part of the login process.

=item account string

Supply an additional account password.  If this token is present,
the auto-login process will supply the specified string
if the remote server requires an additional account password.

=item macdef name

Define a macro. C<Net::Netrc> only parses this field to be compatible
with I<ftp>.

=back

=head1 CONSTRUCTOR

The constructor for a C<Net::Netrc> object is not called new as it does not
really create a new object. But instead is called C<lookup> as this is
essentially what it does.

=over 4

=item lookup ( MACHINE [, LOGIN ])

Lookup and return a reference to the entry for C<MACHINE>. If C<LOGIN> is given
then the entry returned will have the given login. If C<LOGIN> is not given then
the first entry in the .netrc file for C<MACHINE> will be returned.

If a matching entry cannot be found, and a default entry exists, then a
reference to the default entry is returned.

=back

=head1 METHODS

=over 4

=item login ()

Return the login id for the netrc entry

=item password ()

Return the password for the netrc entry

=item account ()

Return the account information for the netrc entry

=item lpa ()

Return a list of login, password and account information fir the netrc entry

=back

=head1 AUTHOR

Graham Barr <gbarr@pobox.com>

=head1 SEE ALSO

L<Net::Netrc>
L<Net::Cmd>

=head1 COPYRIGHT

Copyright (c) 1995-1997 Graham Barr. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut
